Golf Club Head and Method of Making Same

ABSTRACT

A golf club head, preferably a putter head, has a body fitted with inserts having a density greater than that of the club head body. Two cavities are formed in the body. One cavity is adjacent a heel region of the body, and the other cavity is adjacent a toe region of the body. In a preferred embodiment, the inserts and the cavities are provided with a suitable draft angle. The inserts are bonded within the cavities and are subsequently finished using a milling process or the like so that a front surface of each insert is substantially flush with the front face of the body.

This application is a continuation of application Ser. No. 11/086,111filed Mar. 22, 2005,

BACKGROUND OF THE INVENTION

This invention relates generally to golf equipment and, in particular,to a golf club head and a method of making tine golf club head.

It is often desirable to incorporate heel and toe weighting into a golfclub head to increase the moment of inertia of the club head. Thisincreased moment of inertia tends to decrease club head twisting in theevent the golfer strikes the golf bail off-center. In an effort toincrease the moment, of inertia, prior art club heads generally utilizea low-density material (such as aluminum) for a club head body inconjunction with a higher density material for heel and toe weights.U.S. Pat. No. 4,508,350, for example, discloses a golf club putterhaving a high polar moment of inertia provided by forming the club headbody of aluminum. Similarly, U.S. Pat. No. 4,915,385 discloses metallic(e.g., copper) heel and toe weights used in conjunction with alower-density (e.g., aluminum) club head.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a golf club head in accordancewith the present invention;

FIGS. 2A, 28 and 2C are enlarged cross sectional views showing a portionof the golf club head shown in FIG. 1; and

FIG. 3 is an enlarged perspective view of a portion of the golf clubhead of FIG. 1.

DESCRIPTION OF THE INVENTION

With reference to FIG. 1, a golf club head 100, preferably a golf putterhead, in accordance with a preferred embodiment of the present inventionincludes a body 102 having a front face 112, a bottom surface or “sole”114, a heel region 106, and a toe region 104. Body 102 is typicallyattached to a shaft. 110 via a suitable hose! 108 and is suitably formedsuch that it includes two cavities (or “pockets”) 130 and 132 located intoe and heel regions 104 and 106, respectively. Inserts 120 and 122 areconfigured to be received within, attached to, or otherwise integratedwith body 102 such that they substantially fill the respective cavities130 and 132.

In the preferred embodiment, cavities 130 and 132 are configured toreceive the respective inserts 120 and 122 only through openings infront face 112, and are held in place via any suitable bondingtechnique—e.g., epoxy, interference fit, or the like. In the preferredembodiment, cavities 130 and 132 (as well as inserts 120 and 122) areformed with a suitable “draft” (e.g., a five degree draft) to facilitateplacement of inserts 120 and 122, as described in further detail below.Further in accordance with the preferred embodiment, after inserts 120and 122 are placed in cavities 130 and 132, the front surfaces 214 (FIG.2A) of inserts 120 and 122 are milled or otherwise finished so thatthese front surfaces 214 are flush with lace 112.

Body 102 generally comprises any suitable metal, plastic, compositematerial, or combination thereof selected in accordance with variouscriteria as described in further detail below. For example, body 102 maybe made of a metallic material having a relatively low density, e.g.,titanium or a high-purity titanium alloy having a density ofapproximately 3.0 g/cm³ to 7.0 g/cm³. Alternatively, the body 102 may bemade of a composite or plastic material having the desiredcharacteristics. Depending upon the selected material or materials, body102 may be fabricated using any suitable process now known or laterdeveloped, including a variety of conventional casting methods such asinvestment-casting, powdered-metal processing, and/or metal machining.Body 102 is preferably formed using a suitable casting process andthereafter milled to finish the various exposed surfaces, as describedin further detail below.

In the preferred embodiment, cavities 130 and 132 are configured withrespect to body 102 such that inserts 120 and 122 form a portion efface112 of body 102 and are placed at the opposite ends of body 102, i.e. inthe heel and toe regions 106 and 104 of the body 102. This placement ofthe inserts 120, 122 increases the moment of inertia of club head 100when inserts 120 and 122 are fabricated from a material having a densitythat is greater than that of body 102. In this regard, inserts 120 and122 may be fabricated using any suitable material, including variousmetals, plastics, composite materials, or any combination thereof. Inthe preferred embodiment, inserts 120 and 122 are formed of a materialsuch as tungsten having a density ranging from approximately 15.0 g/cm³to 20.0 g/cm³.

It is usually advantageous to fit club head 100 with inserts 120 and 122having substantially the same weight. The present invention, however,also contemplates the use of inserts 120 and 122 having differentweights and/or manufactured from different materials. This might beadvantageous, for example, to compensate for non-symmetrical features ofclub head 100 or to align the center of gravity of club head 100 withthe geometric center of front face 112. Inserts 120 and 122 may be fixedwithin respective cavities 130 and 132 using any suitable method nowknown or later developed, including the use of adhesives and/orconventional metal-joining operations such as soldering, brazing, andthe like. In the preferred embodiment, inserts 120 and 122 are affixedwithin cavities 130 and 132 by using a conventional epoxy adhesive.

FIGS. 2A, 28 and 2C depict the placement of insert 120 within cavity130, as seen in a cross sectional view. As shown in FIG. 2A, cavity 130has a bottom wall 209 and side walls 210. In the preferred embodiment,the side walls 210 are provided with a draft angle alpha, (e.g., a draftangle of approximately five degrees). It will be appreciated that themating side surfaces 212 of insert 120 would have the same draft angle.Insert 120 also has a bottom surface 216. As shown in FIG. 2B, insert.120 is suitably placed within cavity 130 such that, it substantiallyfills the cavity 130 In the preferred embodiment, a layer 218 of epoxyadhesive is applied to the bottom wall 209 and the side walls 210 ofcavity 130 in order to provide permanent bonding of the insert 120within cavity 130,

It will be understood that portions of the front surface 214 of insert120 may not be flush (e.g., at points 220 and 222 in FIG. 2B) withrespect to front face 112 of the body 1.02. Accordingly, the surface 214is preferably milled or otherwise finished so thai the surface 214 asshown in FIG. 2C is flush with front face 112. It will be appreciatedthat the steps illustrated in FIGS. 2A-2C would also be performed forthe insert 122.

FIG. 3 shows the insert 120 as having an inner arcuate surface 306 andan outer arcuate surface 308. It will be understood that the outerarcuate surface 308 generally follows the contour of the toe region 104of the body 102. The insert 120 is preferably configured such that thereis more mass in portion 304 that is below vertical midline 310 than inthe portion 302 that is above vertical midline 310. It is preferablethat, given the total height of insert 120 (as viewed from the frontrelative to the body 102), the insert weight is concentrated such thatthe center of gravity 320 of insert 120 is below vertical midline 310.This configuration of insert 120 assists in lowering the center ofgravity of the club head 100.

Although the invention has been described herein in conjunction with theappended drawings, those skilled in the art will appreciate that thescope of the invention is not so limited. For example, while the presentinvention has been described in terms of golf putters, many other typesof golf clubs would profit from the present invention, including irons,metal woods, etc. Moreover, while titanium and tungsten have been citedas preferred materials for the body and inserts respectively, it will beappreciated that any suitable material now known or later developed maybe used in connection with the present invention, including variousmetals, alloys., composites, ceramics, and the like. These and othermodifications in the selection, design, and arrangement of the variouscomponents and steps discussed herein may be made without departing fromthe scope of the invention as set forth in the appended claims.

1. A method of manufacturing a golf club head, comprising: forming abody having a heel region, a toe region, a front, face, a first cavityin the heel region, and a second cavity in the toe region; forming afirst insert and a second insert; placing the first insert within thefirst cavity; placing the second insert within the second cavity; andforming each of the first and second inserts with a height and ahorizontal midline perpendicular to the height so that a portion of eachof the inserts located below the horizontal midline comprises a volumegreater than a portion of each of the inserts located above thehorizontal midline.
 2. The method of claim 1, further comprisingaffixing the first and second inserts within the first and secondcavities by using adhesive.
 3. The method of claim 1, further comprisingfinishing front surfaces of the first and second inserts to besubstantially flush with the front face by utilizing a milling process.4. The method of claim 1, wherein forming the body further comprisesforming each of the first and second cavities with a plurality of sidewalls, and each of the side walls of the cavities having a draft angle.5. The method of claim 4, wherein forming the first insert and thesecond insert further comprises forming each of the first and secondinserts with a plurality of side surfaces for mating with the side wallsof the first and second cavities, and each of the side surfaces of theinserts having the draft angle.
 6. The method of claim 5, whereinforming the body further comprises forming each of the first and secondcavities with a bottom wall, and forming each of the first and secondinserts with a bottom surface.
 7. The method of claim 6, furthercomprising applying a layer of adhesive to the bottom wall and the sidewalls of the first and second cavities before the first and secondinserts are placed in the first and second cavities.
 8. The method ofclaim 4, wherein the draft angle is approximately 5°.
 9. The method ofclaim 1, wherein forming the body further comprises forming the bodyfrom a first material having a first density, wherein forming the firstinsert and the second insert further comprises forming the first andsecond inserts from a second material having a second density, andwherein the second density is greater than the first density.
 10. Themethod of claim 9, wherein forming the body further comprises providingthe second density at a ratio of at least 2.5:1 with respect to thefirst density.
 11. The method of claim 1, wherein forming the first andsecond inserts further comprises forming each of the first and thesecond inserts with a perimeter having a partial convex surface and apartial concave surface.
 12. A golf club head comprising: a bodycomprising a heel region, a toe region, a front face, a first cavity inthe heel region, and a second cavity in the toe region; a first insertand a second insert located in the first and second cavities,respectively; and wherein each of the first and second inserts has aheight and a horizontal midline perpendicular to the height so that aportion of each of the inserts located below the horizontal midline hasa mass greater than a portion of each of the inserts located above thehorizontal midline.
 13. The golf club head of claim 12, wherein each ofthe first and second cavities comprises a plurality of side walls andeach of the side wails of the cavities has a draft angle, wherein eachof the first and second inserts comprises a plurality of side surfacesfor mating with the side walls of the first and second cavities, andwherein each of the side surfaces of the inserts has the draft angle.14. The golf club head of claim 13, further comprising a layer ofadhesive on the side walls of the first and second cavities to bond thefirst and second inserts in the first and second cavities.
 15. The golfclub head of claim 13, wherein the first and second cavities each have abottom wall, and wherein the first and second inserts each have a bottomsurface.
 16. The golf club head of claim 13, wherein the draft angle isabout 5°.
 17. The golf club head of claim 12, wherein the body is formedof a first material having a first density, wherein the first and secondinserts are formed of a second material having a second density, andwherein the second density is greater than the first density.
 18. Thegolf club head of claim 17, wherein the second density has a ratio of atleast 2.5:1 with respect to the first density.
 19. The golf club head ofclaim 12, wherein each of the first and second inserts comprises a frontsurface, that is substantially flush with the front face of the body.20. The golf club head of claim 12, further comprising an adhesive inthe first and second cavities between the body and the first and secondinserts.
 21. The golf club head of claim 12, wherein each of the firstand second inserts comprises a perimeter having a partial convex surfaceand a partial concave surface.
 22. A method of manufacturing a golf clubcomprising: forming a body having a heel region, a toe region, a frontface, a first cavity adjacent the heel region, and a second cavityadjacent the toe region, wherein each of the first and second cavitieshas a plurality of side walls, and wherein the side walls of thecavities have a draft angle; forming a first insert and a second insert,each insert having a plurality of side surfaces for mating with the sidewalls of the first and second cavities, wherein the side surfaces of theinserts have the draft angle; placing and affixing the first insertwithin the first cavity, wherein the center of mass of the first insertlies below a horizontal midline of the body; placing and affixing thesecond insert within the second cavity, wherein the center of mass ofthe second insert lies below the horizontal midline of the body; andcoupling the body to a shaft.
 23. The method of claim 22, furthercomprising finishing front surfaces of the first and second inserts byutilizing a milling process so that the front surfaces of the first andsecond inserts are substantially flush with the front face.
 24. Themethod of claim 22, wherein forming the body further comprises formingthe body from a first material having a first density, wherein formingthe first and second inserts comprises forming the first and secondinserts from a second material having a second density, and wherein thesecond density is greater than the first density.
 25. The method ofclaim 24, wherein forming the first and second inserts further comprisesforming each of the first and the second inserts from the secondmaterial having the second density in a ratio at least 2.5:1 to thefirst density.
 26. The method of claim 22, wherein forming the first andsecond inserts further comprises forming each of the first and secondinserts with a height and a horizontal midline perpendicular to theheight so that a portion of each of the inserts located below thehorizontal midline comprises a volume greater than a portion of each ofthe inserts located above the horizontal midline.
 27. The method ofclaim 22, wherein forming the first and second inserts further comprisesforming each of the first and the second inserts with a perimeter havinga partial convex surface and a partial concave surface.
 28. The methodof claim 22, wherein the draft angle of the side wails of the cavitiesis about 5°.